[PATCH 05/10] drm/amd/display: temp w/a for DP Link Layer compliance

[Wayne Lin]

From: Aurabindo Pillai <aurabindo.pillai at amd.com>

[Why&How]
Disabling P-State support on full updates for DCN401 results in
introducing additional communication with SMU. A UCLK hard min message
to SMU takes 4 seconds to go through, which was due to DCN not allowing
pstate switch, which was caused by incorrect value for TTU watermark
before blanking the HUBP prior to DPG on for servicing the test request.

Fix the issue temporarily by disallowing pstate changes for compliance
test while test request handler is reworked for a proper fix.

Fixes: 67ea53a4bd9d ("drm/amd/display: Disable DCN401 UCLK P-State support on full updates")
Cc: Mario Limonciello <mario.limonciello at amd.com>
Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: stable at vger.kernel.org
Reviewed-by: Dillon Varone <dillon.varone at amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai at amd.com>
Signed-off-by: Wayne Lin <wayne.lin at amd.com>
---
 .../drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c   | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index 8eaf292bc4eb..b0fea0856866 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -46,6 +46,7 @@
 
 #include "dm_helpers.h"
 #include "ddc_service_types.h"
+#include "clk_mgr.h"
 
 static u32 edid_extract_panel_id(struct edid *edid)
 {
@@ -1181,6 +1182,8 @@ bool dm_helpers_dp_handle_test_pattern_request(
 	struct pipe_ctx *pipe_ctx = NULL;
 	struct amdgpu_dm_connector *aconnector = link->priv;
 	struct drm_device *dev = aconnector->base.dev;
+	struct dc_state *dc_state = ctx->dc->current_state;
+	struct clk_mgr *clk_mgr = ctx->dc->clk_mgr;
 	int i;
 
 	for (i = 0; i < MAX_PIPES; i++) {
@@ -1281,6 +1284,16 @@ bool dm_helpers_dp_handle_test_pattern_request(
 	pipe_ctx->stream->test_pattern.type = test_pattern;
 	pipe_ctx->stream->test_pattern.color_space = test_pattern_color_space;
 
+	/* Temp W/A for compliance test failure */
+	dc_state->bw_ctx.bw.dcn.clk.p_state_change_support = false;
+	dc_state->bw_ctx.bw.dcn.clk.dramclk_khz = clk_mgr->dc_mode_softmax_enabled ?
+		clk_mgr->bw_params->dc_mode_softmax_memclk : clk_mgr->bw_params->max_memclk_mhz;
+	dc_state->bw_ctx.bw.dcn.clk.idle_dramclk_khz = dc_state->bw_ctx.bw.dcn.clk.dramclk_khz;
+	ctx->dc->clk_mgr->funcs->update_clocks(
+			ctx->dc->clk_mgr,
+			dc_state,
+			false);
+
 	dc_link_dp_set_test_pattern(
 		(struct dc_link *) link,
 		test_pattern,
-- 
2.37.3